The temperature of the world has increased in recent years and due to this rising heat, the climatic condition has drastically changed. As a result, the indoor temperature of our habitable houses has increased and the energy consumption is very high which makes eco-friendly building development a very important issue. Building material is involved directly and indirectly with the change of this built environment as every individual material has different properties and they react differently to climatic conditions. As a deltaic country, Bangladesh is blessed with numerous natural resources, such as mud, bamboo and etc. Traditionally, mud is used as the core construction material for building structures. Mud being a really cheap, available, and environmentally friendly building fabric, is used extensively for building development within the country. Mud encompasses an extraordinary capacity of containing heat and low thermal conductivity which moves forward the warm soundness interior of the building compared to other building materials. This paper focuses to find an alternative material to ensure a better thermal performance of the built environment. To do this, 4-5 houses made from mud will be selected as case study and comparative analysis of hourly temperature profile, monthly heating/cooling loads and Resource consumption inside buildings will be done using ECOTECT software simulation. The resultant information from thermal simulation will analyze, compare and discuss the thermal behavior, comfort and energy consumption of mud houses. This research will contribute to suggest an alternative thermally comfortable, low-cost building materials instead of dried brick and advancement of passive and low energy architecture towards a sustainable future.